Until recently, a combination of the useful fungus, Gliocladium catenulatum J1446, developed by Lallemand Plant Care, with Flying Doctors® was only allowed to be used by Belgian and Finnish growers. The Dutch authorities gave the go-ahead at the end of 2015 and now growers in the Netherlands can also rely on the effective Flying doctors® and Prestop® 4B combination – the product name for Gliocladium*. French authorities also approved the product at the beginning of 2016.
The Botrytis fungus (Botrytis cinerea) manifests itself especially during the flowering stage of strawberry and raspberry crops. It is particularly troublesome as, in general, the infection is dormant for a prolonged period, only to breakthrough and cause fruit rot just before or after harvest time.
The Flying Doctors® and Prestop® 4B combination avoids the unpleasant task of spraying. The hives are equipped with a reservoir through which the bumblebees proceed on their way out. The biofungicide sticks to their feet. The bumblebees then swarm out over the hive and leave Gliocladium residue directly on the flowers they visit while pollinating the flowers at the same time.
“Gliocladium is an extremely versatile fungicide,” says Sarah Van Beneden, Product Manager at Biobest. “The fungus settles itself in the same place as Botrytis, whereby the Botrytis eventually loses ground.” But Gliocladium has more to offer. “It produces an enzyme which damages the cell wall of the malicious intruder,” she says. “Because of the versatile nature of the beneficial fungus Gliocladium, there is also no sign of resistance development to Botrytis.”
Using Flying Doctors® saves growers valuable time. Bumblebees work seven days a week, from sunrise to sunset – which means the fungus is continuously controlled and the blossoms enjoy continuous protection. Sarah Van Beneden adds that bumblebees are also exceptionally cost effective thanks to their precise working method. “In the end, much less of the product is needed than with conventional spraying.”
At the end of last year, a trial was conducted at the fruit producer Hennissen (Dutch Limburg). The management team introduced the combination of Flying doctors® with Prestop® 4B in their protected raspberry crops. “We wanted to see with our own eyes how the biological fungus actually works in practice,” says André Hennissen. “Preventive control is extremely important for our raspberries, which blossom for six weeks but are only open for a very short time. We used to spray pesticides every two weeks.”
Hennissen looks back at the trial with satisfaction. “Gliocladium was found in 100% of the flower samples. This eventually led to excellent protection of the fruit. Thanks to the Flying doctors® and Prestop® 4B, we were able to stop chemical spraying altogether during the flowering period. Post-flowering we maintained a reduced number of pesticide sprays.”
Controlling the fungus with a biological solution provided Hennissen with peace of mind. “It is very satisfying to know that the bumblebees are not only pollinating but also controlling disease at the same time.”
After Belgium*, Finland and the Netherlands,** France*** also approved the product in January 2016.
*Until the end of 2015, Prestop 4B was sold in Belgium under the product name Verdera B4 In Belgium. Prestop 4B is authorised to control Botrytis in protected and field grown strawberries and raspberries.
** In the Netherlands Prestop 4B is authorised to control Botrytis in strawberries and raspberries (under protection)
*** In France, Prestop 4B is authorised to control Botrytis in strawberries and raspberries (under protection); the product will be marketed by Biobest France in combination with Prestop under the name Combi-pack Prestop.